U.S. patent number 7,223,362 [Application Number 10/726,524] was granted by the patent office on 2007-05-29 for methods for extinguishing petroleum-based fires, suppressing petroleum-released vapors and cleaning petroleum-contaminated surfaces.
This patent grant is currently assigned to Hans Achtmann. Invention is credited to Peter Riley.
United States Patent |
7,223,362 |
Riley |
May 29, 2007 |
Methods for extinguishing petroleum-based fires, suppressing
petroleum-released vapors and cleaning petroleum-contaminated
surfaces
Abstract
Compositions and methods for emulsifying a petroleum product
that has been spilled upon a portion of the earth's surface or that
is burning are based upon use of a nonionic, primary surfactant
composition comprising a first ethoxylated sorbitol oleate and,
preferably, a second ethoxylated sorbitol oleate, and a nonionic,
secondary surfactant that is capable of stabilizing and
solubilizing the primary surfactant composition such that the
resulting emulsifying compositions have a hydrophilic/lipophilic
balance between about 12.0 and about 13.5.
Inventors: |
Riley; Peter (Paris,
FR) |
Assignee: |
Achtmann; Hans (New Canaan,
CT)
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Family
ID: |
33304062 |
Appl.
No.: |
10/726,524 |
Filed: |
December 4, 2003 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20040206514 A1 |
Oct 21, 2004 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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09987234 |
Oct 29, 2001 |
6660698 |
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09458678 |
Dec 10, 1999 |
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09081461 |
May 19, 1998 |
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08701063 |
Aug 21, 1996 |
5753127 |
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Current U.S.
Class: |
422/42; 422/41;
210/925; 510/365; 510/421; 510/506; 510/422; 510/366; 510/356;
510/188; 210/749 |
Current CPC
Class: |
C09K
23/018 (20220101); C11D 1/825 (20130101); C09K
3/32 (20130101); C11D 11/0052 (20130101); A62D
1/005 (20130101); C11D 11/0041 (20130101); A62D
1/0042 (20130101); C11D 1/74 (20130101); Y10S
210/925 (20130101); C11D 1/667 (20130101) |
Current International
Class: |
B01J
19/16 (20060101); B01F 17/38 (20060101); B01F
17/42 (20060101); C02F 1/68 (20060101); C11D
1/825 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Anthony; Joseph D.
Attorney, Agent or Firm: Clark & Brody
Parent Case Text
This application is a divisional of U.S. patent application Ser.
No. 09/987,234, filed Oct. 29, 2001 now U.S. Pat. No. 6,660,698,
which is a continuation-in-part of commonly assigned U.S. patent
application Ser. No. 09/458,678, filed Dec. 10, 1999, now
abandoned, which is a continuation-in-part of U.S. patent
application Ser. No. 09/081,461, filed May 19, 1998, now abandoned,
which is a continuation-in-part of U.S. patent application Ser. No.
08/701,063, filed Aug. 21, 1996, now U.S. Pat. No. 5,753,127.
Claims
What is claimed is:
1. A method for suppressing production of methane and/or ammonia
vapors by a petroleum or petroleum-based product or other material
undergoing degradation or decay and releasing methane and/or
ammonia vapors, comprising applying to said product or material a
composition comprising: (a) a nonionic primary surfactant
comprising an ethoxylated sorbitol oleate; (b) a nonionic secondary
surfactant selected from the groups consisting of linear
ethoxylated secondary alcohols, polyoxyethylene aryl ethers,
ethoxylated sorbitan monolaurates, ethoxylated fatty acid amides
and ethoxylated fatty acids; wherein said nonionic secondary
surfactant contains about 7 moles to about 26 moles of ethylene
oxide and comprising from about 20 to about 36 weight percent of
said composition, and wherein said nonionic secondary surfactant is
capable of stabilizing and solubilizing said nonionic primary
surfactant such that said composition has a hydrophilic/lipophilic
balance between about 12.0 and about 13.5; and (c) water.
2. A method according to claim 1, wherein the product or material
is a spilled petroleum or petroleum-based product.
3. A method according to claim 1, wherein the material is
compost.
4. A method according to claim 1, wherein the product or material
is disposed in a landfill.
5. A method according to claim 1, wherein the primary surfactant is
ethoxylated sorbitol septaoleate.
6. A method according to claim 1, wherein the secondary surfactant
has a hydrophilic/lipophilic balance of from about 10 to about
17.
7. A method according to claim 1, wherein the composition further
comprises an emulsion-stabilizing agent.
8. A method according to claim 1, wherein the composition further
comprises a polyethylene glycol component having a molecular weight
of from about 200 to about 400.
9. A method according to claim 1, wherein the secondary surfactant
is a linear ethoxylated secondary alcohol having 7 11 moles of
ethylene oxide.
10. A method according to claim 1, wherein the secondary surfactant
is a ethoxylated sorbitan monolaurates having 15 26 moles of
ethylene oxide.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates, in general, to compositions and
methods for dispersing petroleum spills, and for accelerating
biodegradation of such petroleum spills, and especially those that
have occurred upon a body of water or any other surface.
2. Related Art
Crude petroleums, as well as many products derived from them, are
shipped from oil-producing locations to oil-consuming locations in
ocean-going vessels having huge capacities. Accidents in which the
hulls of such vessels are breached and their contents spilled can
cause serious damage to the environment. Unfortunately, such
accidents are not at all uncommon. Land and offshore oil wells also
can be a source of oil spills into ocean waters. Oil spills from
such accidents may quickly spread over many square miles of water
surface. When they occur near, or drift to, shorelines, such spills
are particularly destructive toward local wildlife and plant life.
Petroleum spills of this type also damage boats, fishing gear and
harbor installations; and they greatly diminish the value of the
shore as a recreational resource. If not treated, such spills
require long periods to biodegrade; indeed, about 22 years is
required to completely biodegrade one kilogram of crude oil by
natural processes.
Other oil spills are the result of deliberate actions such as acts
of war, sabotage, and illegal discharge of cleaning fluids that are
employed to clean oil tankers in preparation for carrying a
petroleum product that differs from the last product carried.
Petroleum products flowing through refineries and oil transport
pipe systems are often spilled on land as well. Such land spills
likewise require very long periods; to biodegrade. Furthermore,
since petroleum products are flammable, intense fires often occur
as a result of such spills. Such fires are fed by vapors released
by the petroleum products, such vapors including, e.g., ammonia and
methane vapors. It is therefore highly advantageous to be able to
contain and remove oil spills, and to arrest the vapors so that
they may not enter and pollute the atmosphere, as soon as possible
after the event.
Many methods have been used to remove oil spills from water and/or
land. Such methods include physical removal of the petroleum from
the water or land chemical remediation of the spilled petroleum
through the use of dispersants and so-called "sinking agents," and,
in some cases, intentionally burning floating petroleum slicks.
Chemical remediation through the use of liquid, oil dispersant
agents is the most frequently employed clean-up method because such
liquids can be readily applied to large oil spills and because this
method is generally more cost-effective than physical remediation
methods.
Most of the more effective methods of chemically remediating oil
spills involve the use of various surfactant compositions. A
surfactant is a surface-active agent whose molecules are composed
of groups of opposing polarity and solubility, i.e., surfactants
usually have both an oil-soluble hydrocarbon chain and a
water-soluble group. Surfactants can be anionic, cationic or
nonionic and they may be comprised of mixtures of any of these
types of surfactants. Such surfactant mixtures often include other
chemical agents, such as solvents, that enhance the dispersant
capabilities of the surfactant. However, not all surfactant
compositions are effective in dispersing spilled oil products--and
many of the more effective ones have the drawbacks of being toxic
and/or not biodegradable.
Oil spill dispersant compositions employing a wide variety of
surfactants are found in the patent literature. For example, U.S.
Pat. No. 4,597,893 to Byford et al. teaches a dispersant
composition for treating oil on water. The composition comprises a
nonionic surfactant, an anionic surfactant, a solvent, and water.
The nonionic surfactant can be one or more polyalkoxylated (5 to 55
moles) sorbitol or sorbitan fatty acid esters containing 40 moles
of ethylene oxide and having a hydrophilic/lipophilic balance (HLB)
of 9 to 12. The nonionic surfactant comprises 8 to 58 weight
percent of the overall composition. The anionic surfactant is
preferably a salt of an alkyl aryl sulfonate. The solvent is a
five- to ten-carbon primary alcohol, glycol, or glycol-ether, for
example, ethylene glycol monoburyl ether. A water component also
may be added as desired.
U.S. Pat. No. 3,793,2118 to Canevari et al. teaches dispersal of
oil slicks on water with a dispersant comprising a C.sub.10 to
C.sub.12 aliphatic monocarboxylic acid or sorbitan monoester
thereof, a sorbitan monoester polyoxyalkylene adduct, and a dialkyl
sulfosuccinate salt. The dispersant can be applied to an oil slick
with or without a solvent, such as, for example, paraffin (Isopar).
The total hydrophilic/lipophilic balance of these compositions is
between 9 and 11.5.
U.S. Pat. No. 4,382,873 to Gatellier et al. teaches a dispersant
and biodegradant for oil that has been spilled on water. The
dispersant contains (1) an assimilable nitrogen compound derived
from melarnine, (2) a hydroxy-providing compound such as a
monoalcohol or a mono alkyl derivative of ethylene glycol, (3) an
assimilable phosphorus derivative and (4) at least two of the
following surface-active agents: sorbitan monolaurate, sorbitan
trioleate, sorbitan monooleate, anhydrosorbitol monooleate, an
ethoxylated primary alcohol (C.sub.12 C.sub.13), or PEG (300 400)
mono- or di-oleate.
U.S. Pat. No. 3,959,134 to Canevari teaches an oil collection agent
that surrounds and collects oil that has been spilled on water. The
agent is a mixture of a C.sub.10 to C.sub.20 saturated or
unsaturated fatty acid or the sorbitan monoester thereof (e.g.,
SPANN), and a nonpolar solvent such as isoparaffin.
U.S. Pat. No. 4,146,470 to Mohan et al. discloses a combination of
microorganisms and surfactants to disperse and digest oil slicks.
The microorganism is preferably Micrococcus certificans. The
surfactant mixture contains 15% to 75% by weight of (1) sorbitan
monooleate (SPAN 80) and polyoxyethylene sorbitan monooleate (TWEEN
80), or (2) an alkyl glycoside, or a mixture of (1) and (2). These
surfactants may or may not be diluted in a paraffin solvent
(Isopar). The HLB of the resulting composition is between 6.9 and
9.5.
There is, however, still a need for improved oil dispersant
compositions. This need follows from the fact that many prior art
dispersants; (1) are not always effective in dispersing highly
viscous crude petroleum spills; (2) employ other components (in
addition to nonionic surfactants), e.g., anionic surfactants,
solvents, and dialkyl sulfosuccinate salts, that are not readily
biodegradable, or contain compounds (e.g., certain anionic
surfactants) that are themselves extremely toxic to the
environment, and (3) cannot sustain a hydrophilic/lipophilic
balance at a level that serves to increase their solubility with
water. Others have unacceptably short shelf lives and, hence, must
be mixed in the field, and few, if any, are also capable of serving
as a fire-fighting agent as well as an oil dispersant.
3. Solution to the Problem.
Several of the above-noted patents show that ethoxylated sorbitol
oleates have been used in various dispersants used to treat oil
spills; however, many ethoxylated sorbitol oleate-containing
dispersants also have proven to be rather unstable and, hence, not
well suited for long-term storage and are therefore of rather
limited practical utility. Consequently, there have been many
attempts to increase the stability of ethoxylated sorbitol
oleate-containing oil emulsifying agents by adding other surfactant
ingredients such as, for example, primary alcohols to them.
However, primary alcohols alone have proved to be rather poor
stabilizers for oil dispersants of this kind.
Applicant has, however, discovered that other types of surfactants
having the hereinafter-described attributes can be added to certain
ethoxylated sorbitol oleate-containing oil-emulsifying agents to
form water-miscible compositions that are very effective at
emulsifying spilled petroleum and/or petroleum products and are
particularly characterized by their long shelf lives and by the
fact that they employ only nonionic surfactants that are, in turn,
characterized by their relatively low toxicity to the environment
and by their relatively fast biodegradability. The emulsifying
compositions of the present invention also are capable of
remediating oil spills on land as well as on water.
Applicant's emulsifying compositions have other utilities as well.
For example, they can be used as fire-fighting agents, and
especially against class B (hydrocarbon) fires in addition to class
A (natural fuels), class C (electrical), and class D (metals)
fires. In particular, whether the target petroleum or
petroleum-based product (e.g., oil or fuel) is spilled or burning,
the composition of this invention bounds the petroleum into a fine
emulsion. In the case of burning petroleum, the composition of this
invention encapsulates the petroleum droplets to form an emulsion
and prevents escape of vapors that feed the fire, e.g., ammonia
and/or methane (which are released by the oil), thereby cutting off
the source of and extinguishing the fire. When applied to a
petroleum spill, the same emulsion extracts the petroleum from the
ground or water surface and is of a nature that readily accelerates
the natural biodegradation process of the petroleum while
maintaining a very low level of aquatic toxicity. Moreover, the
herein-described oil dispersant compositions can be used as
cleaning agents in those situations where the surface to be cleaned
has a high hydrocarbon concentration, e.g., airport runways and
aprons, as well as various container walls, for example, those of
rail cars, tanker trucks, sea-going tankers, storage tanks, and
automobile fuel tanks. In still other applications, these
compositions can be used to maintain and clean oil-contaminated
machine tool parts and to maintain the track beds, switches, etc.,
of railway systems. Applicant's compositions may even be used to
accelerate the rate of biodegradation in sewage systems. In
addition, tests on live animals have shown that applicant's
compositions are also exceptionally effective in the safe cleaning
of oil-contaminated wildlife, such as birds, without any observable
side effects. Further, applicant's compositions have been
independently tested and found acceptable for use as cleaning
agents in meat packing and poultry processing plants. As stated
earlier herein, the composition of this invention can also be used
to prevent the escape of (i.e., suppress) vapors released by
petroleum or petroleum-based products, particularly spilled
petroleum or petroleum-based products. Such vapors are typically
ammonia and/or methane vapors. In addition, the compositions can be
used to suppress ammonia and/or methane vapors released at sites
containing materials undergoing biodegradation or decay,
non-limiting examples of which include, e.g., sites containing
petroleum and/or petroleum-based products or other material
undergoing biodegradation or decay and releasing ammonia and/or
methane vapors, compost (including decaying leaves) piles, animal
waste sites, land fills containing petroleum or petroleum-based
products or other material undergoing degradation or decay and
releasing methane or ammonia vapors, and the like.
SUMMARY OF THE INVENTION
The present invention provides improved compositions and methods
that are particularly effective for emulsifying and/or dispersing a
petroleum product that has been spilled upon a portion of the
earth's surface, e.g., upon a body of salt water, a body of fresh
water or a portion of land. The petroleum products that can be
emulsified and dispersed by applicant's compositions can be crude
petroleum, or petroleum-based products such as fuel oil, gasoline,
jet fuel, and the like. Regardless of the exact nature of the
petroleum product spill, applicant's compositions should be
comprised of a nonionic, primary surfactant composition, a
nonionic, secondary surfactant, and varying amounts of water
depending upon the use to which these emulsifying and/or dispersing
compositions will be applied.
Applicant's primary surfactant ingredient is an ethoxylated
sorbitol oleate and more preferably is a composition comprised of a
mixture of ethoxylated sorbitol oleates. That is to say that such
ethoxylated sorbitol oleate mixtures will have a first ethoxylated
sorbitol oleate and at least one other ethoxylated sorbitol oleate.
In one particularly preferred mixture, the first ethoxylated
sorbitol oleate is ethoxylated sorbitol septaoleate and the second
ethoxylated sorbitol oleate is an ethoxylated sorbitol oleate
selected from the group consisting of ethoxylated sorbitol
trioleate and ethoxylated sorbitol hexaoleate. Most preferably, the
nonionic, primary surfactant will comprise from about 45 to about
90 weight percent of the overall, end product, composition--as it
is manufactured--but before it is diluted with water in the
field--if indeed the end product composition is diluted in the
field.
The secondary surfactant ingredient of the herein-described
compositions for dispersing spilled petroleum products is most
preferably a nonionic surficant, or mixture of nonionic
surfactants--and especially those nonionic surfactants having a
hydrophilic/lipophilic balance (HLB) of about 10 to about 17. Most
preferably, the secondary surfactants of the herein-described
compositions will be selected from the group consisting of linear
ethoxylated secondary alcohols, polyoxyethylene aryl ether,
ethoxylated fatty acid amides, ethoxylated fatty acids and
ethoxylated sorbitan monolaurate. If they are so employed, such
linear ethoxylated secondary alcohols preferably will contain from
about 7 moles to about 11 moles of ethylene oxide and have an HLB
of about 10 to about 15. If so employed, a polyoxyethylene aryl
ether ingredient will most preferably have an HLB greater than
15.5. An ethoxylated sorbitan monolaurate ingredient will,
preferably, contain from about 15 moles to about 26 moles of
ethylene oxide and have an HLB of about 15 to about 17. Applicant's
compositions preferably will contain from about 20 to about 36
weight percent (as such compositions are produced, but before they
are further diluted, if they are in fact further diluted, prior to
use in the field) of such a nonionic, secondary surfactant (or
mixture of such surfactants). The secondary surfactant also should
be capable of stabilizing and solubilizing the primary surfactant
to an extent such that the resulting manufactured composition for
emulsifying a petroleum product has an HLB from about 12.0 to about
13.5.
The water component of applicant's manufactured compositions may be
inherently added to applicant's compositions as pan of the
manufacturing process by virtue of the fact that water may be a
component of applicant's oleate ingredient(s) (e.g., about 25 to
35% thereof) and/or by virtue of the fact that water is added as a
distinct ingredient in the manufacturing process. Preferably, the
water in the oleate ingredients and/or secondary surfactant
ingredient(s) and/or the water added as a distinct ingredient in a
separate step in the manufacturing process will be in quantities
such that the resulting emulsifying compositions, as they are
manufactured, will comprise from about 0.05 to about 30 weight
percent water. The water component of the manufactured compositions
of this patent disclosure (i.e., before any addition of water to
such manufactured compositions is carried out in the field) will
preferably be less than about 30 weight percent of the manufactured
product, and even more preferably will constitute less than 20
weight percent of such manufactured products. A separate water
component used in the manufacturing process (ii any is in fact
used) is preferably deionized water, but fresh water or even salt
water may be employed for this purpose.
Certain optional components also may be added to the
oil-emulsifying and/or dispersing compositions of this patent
disclosure. These optional components preferably include an
emulsion-stabilizing agent and/or a polyethylene glycol composition
(and especially a polyethylene glycol having a molecular weight
from about 200 to about 400). Such optional ingredient-containing
oil-emulsifying composition, as manufactured, but before they
undergo any dilution in the field, preferably will contain from
about 1.0 weight percent to about 4.0 weight percent of such an
emulsion-stabilizing, agent, and from about 1.0 weight percent to
about 2.0 weight percent of such a polyethylene glycol ingredient.
When any, or all, of these optional ingredients are employed, it is
highly preferred that resulting compositions for emulsifying
spilled petroleum, nonetheless, have the 12.0 to 13.5 HLB value
sought in those compositions that do not contain any optional
ingredients. It also should be noted that, regardless of whether or
not these optional ingredients are employed, the end product
compositions for emulsifying spilled petroleum products are also
particularly characterized by their ready biodegradability, low
levels of toxicity to the environment, wide range of thermal
stability, ease of use (owing to the fact that they can be premixed
long before use without undergoing intervening phase separation)
and, if need be, their ability to fight fires as well as disperse
oil.
To further enhance the rate of biodegradation of the emulsifying
compositions of this patent disclosure in situations where the
spill site is deficient in nitrogen, phosphorus and oxygen, small
amounts of inorganic, commercially available fertilizers, such as
mixtures of urea formaldehyde and potassium orthophosphates, also
may be added to applicant's compositions as additional optional
ingredients. These optional fertilizer ingredients are preferably
dissolved in water and added to applicant's manufactured products
(again, before such products are diluted in the field) in
concentrations such that no one of them forms more than about 0.5%
of the total weight of the pre-field-diluted emulsifying
compositions of this patent disclosure. If it is also desired to
lower the freezing point of these emulsifying compositions, a
nontoxic solvent such as, for example, diethylene glycol monobutyl
ether also may be added as yet another optional ingredient. This
ingredient, if used at all, will be added in concentrations such
that the diethylene glycol monobutyl ether constitutes from about
1.0 to about 10.0 weight percent of the manufactured, end product
composition.
In some of the most preferred compositions of this patent
disclosure, prior to any field dilution, the ethoxylated sorbitol
oleate ingredient will be a mixture of ethoxylated sorbitol oleates
comprising (1) about 45 to about 50 weight percent of a first
ethoxylated sorbitol oleate such as ethoxylated sorbitol
septaoleate and wherein said ethoxylated sorbitol oleate contains
from about 35 moles to about 45 moles of ethylene oxide; and (2)
from about 9 to about 10 weight percent of a second ethoxylated
sorbitol oleate, and especially those selected from the group of
oleates consisting of ethoxylated sorbitol trioleate and
ethoxylated sorbitol hexaoleate. Ethoxylated sorbitol trioleate and
ethoxylated sorbitol hexaoleate ingredients containing about 40
moles to about 50 moles of ethylene oxide are particularly
effective as second, or co-surfactant, ethoxylated sorbitol
oleates. The remainder of these most preferred compositions will be
comprised of from about 20 to about 36 weight percent of the
secondary surficant and from about 0.05 to about 30.0 weight
percent water.
The present invention also involves the use of certain hereinafter
more fully described methods of contacting spilled petroleum with
applicant's emulsifying compositions. To these ends, applicant's
compositions may be added to a body of oil-polluted water, or land,
in widely varying "loading" amounts and/or composition
concentrations depending on the end result desired, the type of oil
that has been spilled and/or the existing field conditions. It also
should be noted that, for the purpose of this patent disclosure the
terms "loading," "dosage," etc., should be regarded as being
synonymous.) Be that as it may, a "10% solution" of the
herein-disclosed compositions may be thought of as a mixture that
contains 10% by volume of the various surfactant ingredients (and
optional ingredients, if any are used) that constitute the
manufactured product and 90% by volume of locally added water. Such
a 10% solution may, however, be even further diluted under certain
circumstances. For example, some of the most preferred surfactant
concentrations of applicant's compositions will be actually used in
concentrations as low as about 3 volume percent of the overall
manufactured composition (for example, such relatively low
concentrations are effective when applied, with high shear, to
spills of lighter petroleum products, such as jet fuel, gasoline
and the like). On the other hand, solution concentrations of about
20 volume percent of the manufactured composition and 80 volume
percent local water are particularly effective in dispersing
somewhat heavier petroleum products (such as "light fuel oils") and
lubricating oils, especially when only low shear can be applied. In
general, spills of oils heavier than No. 4 lubricating oils, but
lighter than No. 6 fuel oil, will call for use of oil-emulsifying
manufactured compositions of this patent disclosure diluted to an
extent such that a locally provided water component will comprise
from about 80 to about 94 volume percent of the resulting mixture.
Those compositions of this parent disclosure used to treat oil
spills on land also will preferably be diluted to an extent that
they comprise from about 80 to about 94 volume percent water, and
those compositions of this patent disclosure that are applied in
the context of an oil spill and fire also will most preferably
comprise about 94 volume percent water and about 6 volume percent
of applicant's compositions.
In general, spills of petroleum products less viscous than say, No.
6 fuel oil and "bunker C" can be cleaned up using the manufactured
compositions of this patent disclosure that have been diluted with
water in the field. Such field dilution of the manufactured forms
of the herein-described compositions is generally prescribed when
the spilled oil is "lighter than" No. 6 fuel oil. For example,
spills of petroleum products lighter than No. 6 fuel oil may be
treated with applicant's compositions that have been diluted with
water in the field to such an extent that the resulting
manufactured composition/local water mixture that is applied to the
spill will, most preferably, be comprised of from about 10 to about
90 volume percent of the locally provided water (that is to say,
another 10 to 90 volume percent of local water will be added,
regardless of the fact that a given manufactured composition may
itself already be comprised of from about 0.05 to about 30 weight
percent water).
Indeed, in the case of spills of very light petroleum products such
as gasoline, jet fuel and the like, manufactured compositions/local
water mixtures comprising up to 97 volume percent of local water
(and hence, 3 volume percent of manufactured composition) may be
employed, especially local agitation (e.g., provided by a ship's
wake) also is available.
When the spilled petroleum product is a heavier petroleum product
(e.g., crude petroleum and, generally speaking, a fuel oil as heavy
as No. 6 fuel oil), a particularly preferred method of application
is to apply a manufactured composition having no more than about 30
weight percent water (and more preferably a manufactured
composition having no more than about 10 weight percent water) to
the spilled oil. In other words, the manufactured composition is
applied without any addition of water in the field just prior to
use. Water may, however, be added to the resulting manufactured
composition/spilled oil system after the manufactured composition
is deployed upon the spilled oil.
Applicant has also found that the herein-described manufactured
compositions (that is, those compositions existing prior to any
field dilution with locally available water) can produce total
emulsification with about one (1) part of undiluted composition per
about five (5) pans of a spill of No. 6 oil or bunker C oil. Most
heavy crude oils can be emulsified by one (1) part of undiluted
composition to ten (10) parts of oil. In all cases, the application
of the compositions of this patent disclosure and the resulting
emulsions vastly reduce the tendency of oil slicks on water to
adhere to rock surfaces.
In many cases an emulsifying effect may be all that is required
and/or desired to disperse a given oil spill, but in most cases
biodegradation of the emulsified oil/dispersant combination is the
more desired end result. In any case, the compositions of the
present invention are highly biodegradable in the context of such
oil spill emulsifications. Applicant's tests have shown that most
emulsified oil/dispersant systems produced by the herein-described
compositions will biodegrade by about 80% within four (4) days of
application of the herein-described compositions to an oil spill in
water. Indeed, applicant has found that even within the first three
(3) hours after application of applicant's compositions, about 10%
biodegradation of the oil/dispersant system is obtained. In other
tests applicant found that up to about 97% biodegradation was
obtained within 28 days after application. In yet another
laboratory test, total elimination of the oil/dispersant
combination was observed within 8 days after application of some of
applicant's compositions to certain "light" petroleum products.
The present invention further provides methods of using the
composition of this invention to: (i) extinguish fires occurring in
petroleum or petroleum-based products, (ii) clean surfaces
(including the body surfaces of wildlife, e.g., birds) contaminated
with petroleum and/or petroleum-based product, (iii) accelerate
biodegradation rate of petroleum or petroleum-based product, e.g.,
in a sewage system, and (iv) suppress production of methane and/or
ammonia vapors by a petroleum or petroleum-based product or other
material undergoing biodegradation or decay and releasing methane
and/or ammonia vapors.
DETAILED DESCRIPTION OF THE INVENTION
1. Particularly Preferred Formulations Re: Certain
Applications.
As previously stated, applicant has found that particularly good
oil emulsification results are obtained when the secondary
surfactant of the present invention stabilizes and solubilizes the
primary surfactant composition to a degree such that the resulting,
manufactured end product compositions (before any field dilution of
such manufactured compositions takes place) have a
hydrophilic/lipophilic balance (HLB) between about 12.0 and about
13.5. Those skilled in this art will appreciate that the term "HLB"
as used herein is a well-known measure of the relative
hydrophilicity or lipophilicity of a surfactant composition.
Generally speaking, HLB values are obtained by dividing the
molecular weight of the hydrophilic component of a compound by the
molecular weight of the compound and multiplying the resulting
number by selected adjuster values known to those skilled in this
art. HLB values range on a scale from 1 to more than 20, with 1
indicating the least hydrophilic and 20 and above indicating the
most hydrophilic.
Applicant has found that the stability of the dispersant/spilled
oil emulsions produced by the compositions of this patent
disclosure can be further increased when small amounts of an
emulsion-stabilizing agent are included in applicant's
compositions. These emulsion-stabilizing agents are often used to
provide steric stabilization of dispersed particles (for example,
literature published by Imperial Chemical Industries PLC (ICI)
suggests use of their Hypermer A409.RTM. and Hypermer A394.RTM.
compositions for this purpose). Applicant has, however, found that
the inclusion of such emulsion-stabilizing agents in the
herein-described compositions for disversinc, spilled petroleum
products greatly increases the stability of the resulting
petroleum/composition emulsion. This is an important finding
because the increased longevity of the petroleum/composition
emulsion enables the emulsion to be more completely biodegraded.
Some of the better descriptions of such emulsion-stabilizing agents
are found in the technical literature published by their
manufacturers, and therefore, applicant hereby incorporates by
reference the following publication describing the properties of
ICI's Hypermer.RTM. Polymeric Surfactants and Dispersants for
Industrial Applications", ICI Americas Inc., 1994. Regardless of
the identity of their supplier, however, such emulsion-stabilizing
agents may constitute from about 1.0 to about 4.0 weight percent of
the overall manufactured compositions of this patent
disclosure.
2. Particularly Preferred Methods of Formulating and Deploying
Compositions
To prepare the emulsifying compositions of the present invention,
the Primary surfactant composition is preferably made by first
combining the first and the second ethoxylated sorbitol oleates
under light, nonaerating agitation. If desired the
emulsion-stabilizing agent and/or the polyethylene glycol are
combined under moderately high shear conditions and then blended
with the primary surfactant composition. In some of the more
preferred embodiments of this invention, the secondary surfactant
is added to the primary surfactant composition by blending it under
nonaerating shear conditions. Finally, the water component, if
desired, is preferably added by blending under low shear
conditions. Again, it should be understood that additional water
can be incorporated into the manufactured compositions of this
patent disclosure at a later time, e.g., just prior to use, so that
smaller volumes of the manufactured compositions of this parent
disclosure may be transported to a spill site.
The emulsifying compositions of the present invention may be
applied to petroleum spills on water or on land by conventional
methods known to those skilled In the oil spill remediation arts,
e.g., using various tank and spray nozzle devices or example,
applicant's emulsifying compositions may be sprayed directly on
petroleum spills on water or on land with a small diameter hose
equipped with a spray nozzle to supply a uniform spray. It also
should be noted that it is not necessary to apply the compositions
using a high-pressure hose. For large petroleum spills, applicant's
compositions may be applied by using a helicopter equipped with
tanks having a dump spout that can be operated from within the
helicopter or such helicopters may be provided with tanks and a
pipe manifold systems that are affixed to a plurality of spray
nozzles.
For petroleum spills on land, dispension of the emulsifying
compositions of this patent disclosure may be followed by physical
agitation of the soil and then flushing with water. Alternatively,
applicant's compositions also may be dispensed under pressure, for
example, by a conventional fire extinguisher, whereby the pressure
supplied by such a device mixes the emulsifying composition with
the petroleum and simultaneously flushes it away.
Because of its emulsifying properties, the composition of this
invention is useful in other applications as well, including, e.g.,
extinguishing fires occurring in petroleum or petroleum-based
products, cleaning surfaces (including the body surfaces of
wildlife, e.g., birds) contaminated with petroleum and/or
petroleum-based product, accelerating biodegradation rate of
petroleum or petroleum-based product (e.g., in a sewage system),
and suppressing production of methane and/or ammonia vapors by a
petroleum or petroleum-based product or other material undergoing
biodegradation or decay.
Thus, one aspect of the present invention is directed to a method
for extinguishing a fire occurring in a petroleum or
petroleum-based product and caused by vapors released by the
product, involving applying the composition of this invention to
the fire and the product. As stated previously herein, the
composition of this invention encapsulates the petroleum droplets
to form an emulsion and prevents escape of vapors that feed the
fire, e.g., ammonia and/or methane (which are released by the
petroleum or petroleum-based product), thereby cutting off the
source of and extinguishing the fire.
A further aspect of the present invention is directed to a method
for cleaning a surface contaminated with petroleum and/or
petroleum-based product, involving applying the composition of this
invention to the surface. Non-limiting examples of suitable
surfaces include those of airport runways, rail cars, tanker
trucks, sea-going tankers, storage tanks, automobile fuel tanks,
machine tool parts, track beds, railway system switches, and meat
packing and poultry processing plants. The surface can also be the
body surface of a wildlife member, e.g., birds.
Yet another aspect of the present invention is directed to a method
for accelerating biodegradation rate of a petroleum or
petroleum-based product, involving applying the composition of this
invention to the product. In one embodiment of this method, the
product is disposed in a sewage system.
A still further aspect of this invention is directed to a method
for suppressing production of methane and/or ammonia vapors by a
petroleum or petroleum-based product or other material undergoing
biodegradation or decay and releasing ammonia and/or methane
vapors, involving applying the composition of this invention to the
product or material.
This invention is further illustrated by reference to the following
tests conducted upon various formulations of the compositions of
this patent disclosure with respect to their dispersion abilities,
biodegradation, and toxicity.
3. Test Formulations.
Three emulsifying compositions were prepared having the following
three formulations A, B, and C:
Emulsifier Formulation A
45 weight percent--Ethoxylated sorbitol septaoleate, containing 40
moles of ethylene oxide.
9 weight percent--Ethoxylated sorbitol trioleate, containing 40 to
50 moles of ethylene oxide.
36 weight percent--linear ethoxylated secondary alcohol, containing
7 to 11 moles of ethylene oxide and having an HLB of between 10 and
15, preferably 13.
10 weight percent--water.
Emulsifier Formulation B
50 weight percent--ethoxylated sorbitol septaoleate, containing 40
moles of ethylene oxide.
10 weight percent--ethoxylated sorbitol hexaoleate, containing 50
moles of ethylene oxide.
20 weight percent--polyoxylethylene aryl ether, having an HLB of
greater than 15.5
20 weight percent--water.
Emulsifier Formulation C
45 weight percent--ethoxylated sorbitol septaoleate, containing 40
moles of ethylene oxide.
9 weight percent--ethoxylated sorbitol trioleate.
26 weight percent--ethoxylated sorbitan monolaurate.
20 weight percent--water.
a) Dispersion
Emulsifier formulation A was tested using a conventional low-energy
swirling flask dispersant effectiveness test. This test is more
fully described in 40 CFR Section 300 and said regulation is
incorporated into this patent disclosure. The specific oil types
used in applicant's test were two standard preference oils, that
is, Prudhoe Bay Crude and South Louisiana Crude (a lighter oil than
the Prudhoe Bay Crude). The test was performed in "artificial sea
water" (made from Instant Ocean.RTM.) made to a salinity of 35
parts per thousand. One part (by weight) of emulsifying formulation
A was used to 10 parts (by weight) of oil. The test was done with
three or four replicate samples. Results were measured as the
UV-VIS spectrophometric absorbance at 340 nm. 370 nm or 400 nm. The
results of these tests are expressed below as the percentage of the
oil remaining dispersed for 10 minutes after all agitation had
ceased. Those skilled in this art will appreciate that in the oil
remediation arts, a dispersion of 45% of the oil in such tests is
regarded as being an acceptable test result. The results of
applicant's tests are given in Table I and Table II.
TABLE-US-00001 TABLE I % Dispersibility of Prudhoe Crude Replicate
1 Replicate 2 Replicate 3 Absorbance 45 54 47 at 340 nm Absorbance
44 53 46 at 370 nm Absorbance 43 53 45 at 400 nm Average = SD 44 =
1 53 = 1 46 = 1 Overall 48 = 4 average = SD
TABLE-US-00002 TABLE II % Disversibility of South Louisiana Crude
Replicate 1 Replicate 2 Replicate 3 Replicate 4 Absorbance 65 68 67
65 at 340 nm Absorbance 64 67 67 64 at 370 nm Absorbance 63 66 65
63 at 400 nm Average = SD 64 = 0.7 67 = 1.0 66 = 0.9 64 = 0.7
Overall 65 = 1.3 average = SD
Tables I and II clearly show that emulsifying, formulation A
disperses 48% of the Prudhoe Bay Crude and 65% of the South
Louisiana Crude.
Applicant also conducted emulsifying and dispersing tests with
emulsifying formulation A using concentrations as low as about 3%
solutions with respect to "lighter" oil products such as No. 2
diesel oil, under moderately high shear conditions. However,
applicant also found that if less agitation is available, somewhat
higher concentrations, e.g., 15% solutions, were often required to
emulsify and disperse a like amount of the No. 2 diesel oil. By way
of contrast, in order to emulsify and disperse No. 6 fuel oil, a
100% solution of formulation A was applied at a ratio of one (1)
part of composition to 10 parts of oil under moderate agitation to
produce the desired emulsification effects.
b) Biodegradation
The relatively quick and extensive biodegradation property of the
oil-emulsifying compositions of this patent disclosure is one of
their more important properties. It was tested using various tests
known to the art including the E.M.P.A. test (the E.M.P.A. is a
Swiss government organization charged with certifying
oil-dispersant and emulsifying compositions). To this end, a
standard test (EMPA SOP 720) was performed on emulsifying
formulation A to determine the rate of biodegradation of this
formulation in combination with an oil sludge over a period of 28
days. The amount of degradation was determined by measuring the
percentage of the initial total oxygen concentration. In such
tests, applicant found that about 73% of a combination of
emulsifying formulation A/oil sludge (at a concentration of 118 mg
of formulation A per liter of oil sludge) was biodegraded by day 3
of the experiment, and about 81% was biodegraded day 21. The
further results of this test are shown in Table III.
TABLE-US-00003 TABLE III % Initial Total Oxygen Day Concentration
(TOC) 0.1 10 1 30 3 73 7 75 14 79 21 81 28 81
Consequently, these test indicate that the values for the
biodegradation of emulsifying formulation A in combination with oil
sludge are well within the acceptable, range for certification of
emulsifying formulation A by the E.M.P.A.
Applicant's own laboratory and field tests showed that more than
81% degradation of a combination of oil and emulsifying formulation
A was observed within four (41) days of application. In these
tests, about 10% of the biodegradation occurred within the first
three (3) hours after application of formulation A. In other tests,
more than 97% of the oil/emulsifying formulation A combination was
biodegraded after 28 days. Total elimination of the oil/formulation
A combination in eight (8) days was observed in vet another
laboratory test. The significance of these results can be better
appreciated when one considers that natural biodegradation of one
(1) kilogram of crude oil may take as long as 22 years.
c) Toxicity
Another advantageous attribute of applicant's
emulsifying/dispersant compositions is their low toxicity,
especially toward aquatic life. In order to verify this low
toxicity, a sample of formulation B (as described above) was tested
for toxicity against two aquatic organisms, brine shrimp (Artemia
sp.) and a species of fish (Fundulus heteroclitus). The test
procedure involved exposing the organisms to increasing
concentrations of emulsifying formulation B alone and to a
combination of equal amounts of emulsifying formulation B and
diesel oil and determining, the LC.sub.50 (the concentration of
formulation B alone or formulation B/oil combination that kills 50%
of the organisms) after 8 hours of exposure for the shrimp and 96
hours of exposure for the fish. The LC.sub.50 values for
emulsifying formulation B alone were compared with LC.sub.50 values
for other dispersants of comparable efficiency as listed in the
National Contingency Plan defined in 40 CFR Section 300. The
results are shown in Table IV.
TABLE-US-00004 TABLE IV LC.sub.50 (ppm after 96 LC.sub.50 (ppm
after 48 hours) for hours) for Dispersant Fundulus Artemia
Emulsifying 4900 2500 formulation B D-9 115 630 D-27 100 60 D-61
180 60 D-62 71 8 D-64 109 155
The data in Table IV show that, for example, only 115 ppm (parts
per million) of product D-9 will kill one-half of the fish in 96
hours, whereas 4900 ppm of applicant's emulsifying formulation B is
required to kill one-half of the fish in the same period. For
Artemia sp., the comparative dispersants kill one-half of the
shrimp in 48 hours at concentrations of 8 to 630 ppm. Emulsifying
formulation B by contrast, had an LC.sub.50 of 2500 ppm against
Artemia sp. These tests indicate that emulsifying formulation B is
less toxic than comparative dispersants by an order of
magnitude.
When emulsifying formulation B was mixed with an equal amount of
diesel oil and this diesel oil/emulsifier combination was tested
for toxicity against organisms in the same way as described above,
the LC.sub.50 for Artemia sp. was 1500 ppm, and the LC.sub.50 for
Fundulus sp. was 1400 ppm. Again, these toxicity values are far
lower than the LC.sub.50 values shown in Table IV for comparative
dispersants without oil.
The above disclosure sets forth a number of embodiments of the
present invention. Those skilled in this art will however
appreciate that other embodiments, not precisely set forth, also
could be practiced under the teachings of the present invention and
that the scope of this invention should only be limited by the
scope of the following claims.
* * * * *